FYI (for your information), Other is information that the iPod can no longer read. In other words, the information has become corrupted. Neither iTunes not an iPod can read that information and it can not be "opened".
There will always be a small amount of Other on an iPod. If that figure becomes too large, or you discover that some of your music is no longer available on the iPod (i.e. the iPod can't read it), a Restore, using iTunes is the method to reduce it and put good copies of your music back onto the iPod.
That's one reason why you must always keep your iTunes Library in working order; do not rely on an iPod as the only source of your music or as a backup of it. It isn't. Also maintain a backup on a seperate drive.